The project will pilot in San Francisco before it rolls out country-wide.
Babies were born 23 grams heavier during Beijing's fresh air Olympics period.
Chinese capital will close last major coal plant next year in bid to avert economic costs of pollution.
Almost 3,000 fines handed out as French capital seeks to tackle dangerous levels of particulate matter.
Ozone is linked to asthma, heart disease, premature death, and an array of pregnancy complications